The apparatus, methods, and systems described herein relate to determining end-of-life conditions for products and/or systems and providing ways to communicate end-of-life to a customer, owner, operator, or other interested party. As described herein, the term end-of-life (EOL) refers to the point in time in a product's life span wherein the product is no longer operational, no longer useful for its intended purpose, or is not economical to operate (as determined by said customer, owner, operator, or other interested party).
It is generally understood that many products have a life span, the life span typically defined by the manufacturer of the product. Manufacturers often estimate a life span on a sampling of data; as an example, a lamp manufacturer may randomly select some number of lamps from a much larger group, measure the operating hours until product failure for the selected lamps, average the measurements, and report the average as the life span for all lamps of the same make and model as those few tested. In this example, the end-of-life (EOL) condition is defined as the point when the product fails and typically occurs at the end of the product's life span; of course, if the product can be repaired and it is advantageous to do so, this EOL condition does not occur at the end of the life span.
Estimating a life span in this fashion is only somewhat accurate and does not take into account varying operating conditions which may affect EOL. For example, a customer could operate a lamp according to the manufacturer's recommendations and have a reasonable estimate of life span, but then change the operating conditions and have no idea how the life span has been impacted. Further, estimating a life span in this fashion does not take into account the different ways in which a customer, owner, operator, or interested party may define EOL conditions; for example, an owner may want to define EOL with respect to economic factors (e.g., cost to operate) rather than product failure. In practice, there could be multiple EOLs for a product and/or system, not all of which occur at the very end of the life span and not all of which can be estimated by the manufacturer.
Herein lies a problem—customers, owners, operators, and the like (hereafter referred to as users) typically do not have the expertise or information available to determine an accurate or user-relevant life span for a product given their unique operating conditions and criteria for end-of-life and further, may be completely unaware of the true performance of the product and/or system over time. This can lead to an inability to adequately prepare for the EOL of a product and/or system (e.g., by securing funds for a replacement product) and an inability to recognize opportunities for reducing cost (e.g., by operating under different conditions to extend a product's life span, identifying alternative/replacement products which cost less to operate, etc.).
One challenge for the user is identifying one or more end-of-life (EOL) conditions for a product and/or system (hereafter referred to as a product) when the EOL is based on performance or economics but the product itself still appears to function (i.e., has not experienced product failure). Using the aforementioned example of a lamp, a user can readily recognize a lamp that has burnt out (i.e., a product failure) but is typically unable to recognize when the lamp is consuming twice as much power for a given light output as it did initially; the latter may be related to lamp lumen depreciation (LLD), a phenomenon in which the lamp produces less light for the same power input over time.
Developing accurate life spans for lighting systems and/or lamps including light sources which experience LLD is further complicated because of the different operating modes available. For example, some lighting systems are operated at a constant wattage; over time LLD is manifested as a noticeable decrease in the light produced by the lighting system. In this example, a user would likely notice this decrease and know an EOL condition was impending. However, not all light sources deteriorate at the same rate or fail in the same manner. For example, an LED will simply become more and more dim until any light output is indiscernible—and therefore never reach a product failure-based EOL—whereas some light sources burn out or otherwise fail long before they reach any economic-based EOL. Alternatively, if a lighting system is operated in constant light mode (i.e., where incremental power increases maintain near-constant light output despite LLD), there is no visual indication that the lamp is degrading so a user is often unaware of an impending EOL condition regardless of how EOL is defined.
Thus, there is a need to provide users with the tools to adequately assess the life span of a product and further, tools to reassess the life span of a product as operating conditions change and EOL conditions are defined. This need is particularly fervent for users of lighting systems (or components thereof) because of the longevity of the product (e.g., some LEDs can be operated for tens of thousands of hours) and the economic impact to operate the product over time (e.g., operating dozens of HID lamps for several hundred hours per year for several years can cost several thousands of dollars in energy consumption). Thus, there is room for improvement in the art.